Molecular Interaction and Energy Transfer between Human Serum Albumin and Polyoxometalates

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• 作者：Guangjin Zhang ; Bineta Keita ; Jean-Claude Brochon ; Pedro de Oliveira ; Louis Nadjo ; Constantin T. Craescu ; Simona Miron
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：February 22, 2007
• 年：2007
• 卷：111
• 期：7
• 页码：1809 - 1814
• 全文大小：242K
• 年卷期：v.111,no.7(February 22, 2007)
• ISSN：1520-5207

文摘

As a step toward the elucidation of the mechanistic pathways governing the known bioactivity ofpolyoxometalates (POMs), two representative molecules of this class of chemicals, the wheel-shaped[NaP₅W₃₀O₁₁₀]^14- (P5W30) and the Keggin-type anion [H₂W₁₂O₄₀]^6- (H2W12), are shown, by two independenttechniques, to interact with the fatty-acid-free human serum albumin (HSA). The excited-state lifetime of thesingle tryptophan molecule of this protein is dramatically decreased by the binding. The quenching mechanismis found to constitute the first example of energy transfer between HSA and POMs. Such molecular recognitionis believed to be a key step for subsequent evolution of the systems. Circular dichroism (CD) was used toassess the structural effects of POM binding on HSA and to confirm the interaction revealed by fluorescencestudies. CD experiments showed that the two POMs have different effects on the secondary structure of theprotein. Binding P5W30 partially unfolds the protein whereas H2W12 has no remarkable effect on the structureof the protein.